Multiflash device for close-up photography

ABSTRACT

The zonal lumen output of a flashcube (or magicube) is reduced by approximately 50% to provide a soft diffused flash of light for taking pictures at close range (60 to 120 cms.). The reduction in light intensity is effected by replacing the aluminized plastic reflector with a reflector component that is composed solely of white plastic and thus has a non-specular surface which attenuates the light without substantially changing its spectral characteristics.

United States Patent [191 Buzalski [111 3,858,038 Dec. 31, 1974MULTIFLASH DEVICE FOR CLOSE-UP PHOTOGRAPHY [75] Inventor: Bruce T.Buzalski, Dover, NJ.

[73] Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

[22] Filed: Dec. 12, 1973 [2]] App]. N0.: 423,970

[52] US. Cl. 240/l.3, 431/92 [51] Int. Cl. G03b 15/02 [58] Field ofSearch 240/13; 95/11 L;

[56] References Cited UNITED STATES PATENTS 4/1966 Anderson et al.240/].3 X 8/1971 Slomski 240/].3

OTHER PUBLICATIONS Boundy and Boyer, Styrene, lts Polymers, Copolymersand Derivatives; Reinhold Publishing Corp., 1952; page 1197.

Primary ExaminerFred L. Braun Attorney, Agent, or Firm-D. S. Buleza [57] ABSTRACT The zonal lumen output of a flashcube (or magicube) isreduced by approximately 50% to provide a soft diffused flash of lightfor taking pictures at close range (60 to 120 cms.). The reduction inlight intensity is effected by replacing the aluminized plasticreflector with a reflector component that is composed solely of whiteplastic and thus has a non-specular surface which attenuates the lightwithout substantially changing its spectral characteristics.

4 Claims, 3 Drawing Figures BACKGROUND OF THE INVENTION 1. Field of theInvention This invention relates to photographic light sources and hasparticular reference to an improved multiflash unit for a camera.

2. Description of the Prior Art Disposable multiflash units such asflashcubes and magicubes are well known in the art. While these devicesachieved the desired objective of providing a disposable and-compactlight source for taking a series of pictures, they employ a reflectorwhich has a highly specular or mirror-like surface and is thusspecifically designed to direct as much light as possible onto thesubject being photographed so that proper exposure of the film willoccur over a wide range of camera-tosubject distances. The reflectorsurface generally consists of a plastic member that is coated with athin layer of vaporized aluminum.

However, it has been found that the flash of light produced by suchprior art units is too intense when photographs, such as portrait shots,are taken at close range (from about 2 to 4 feet or 60 to 120 cms.). Theintense flash of light at this distance has a tendency to overexpose thefilm and produce hot spots of the center of the picture and, moreimportantly, blinds and startles the person being photographed. This isparticularly distressing when close-ups of young children or babies arebeing taken.

It would accordingly be very advantageous and desirable to have aninexpensive multiflash unit that would provide a soft" diffused beam oflight for taking closeup pictures and which would also beinterchangeable with and use the same type of photoflash lamps as thoseemployed in the flashcubes and magicubes now on the market.

SUMMARY OF THE INVENTION The aforesaid objectives are achieved inaccordance with the present invention by replacing the specularaluminum-coated reflector with a reflector component that is composedentirely of white plastic that has a non-specular surface whichcontrollably attenuates the light rays which it reflects. The contour ofthe reflector is identical to that used previously and the lightattenuation effected by the change in reflector surface is such that thebrightness of the light flash is reduced by ap proximately 50% eventhough identical lamps are used.

By eliminating the vacuum-metallizing operation heretofore required, thepresent invention also reduces the manufacturing cost of the improvedmultiflash unit. The white plastic reflector component also provides avisual difference which immediately identifies the portrait" cube andprevents it from being confused with standard flashcube or magicubeunits now on the market.

BRIEF DESCRIPTION OF THE DRAWING A better understanding of the inventionwill be obtained from the exemplary embodiment shown in the accompanyingdrawing, wherein:

FIG. 1 is a perspective view of a flashcube which embodies the presentinvention;

FIG. 2 is an exploded view of the various components employed in theflashcube shown in FIG. 1; and

FIG. 3 is a plot comparing the light output characteristics of aconventional lamp-reflector module used in a standard flashcube and thenovel lamp-reflector module employed in the improved flashcube of theinvention.

DESCRIPTION OF THE PREFERRED EMBODIMENT A portrait flashcube 10 fortaking close-up pictures is shown in FIG. 1. As will be noted, itcomprises a plastic base member 12 that is fitted with a cubical cover14 of suitable clear plastic which protectively encloses a reflectorcomponent 16 that defines a concave reflector element or surface 17 foreach of the four photoflash lamps 18 mounted on the base member 12. Thelead wires 20 of the flashlamps 18 extend through openings in the basemember 12 and are bent around an annular collar 22 on the base memberand thus serve as contacts or terminals for the flashcube 10. The basemember 12 is also provided with a protruding post 24 that has four cogsor teeth" which permit the flashcube 10 to be inserted into a suitablesocket on the camera and sequentially rotated in the customary fashionas the pictures are taken and the film is advanced.

As illustrated in FIG. 2, the reflectorl6 is preferably formed in onepiece and can be conveniently injection molded from suitable plastic. Itis so shaped that it fits snugly within the protective cover 14 toprovide a subassembly that is slipped over the mounted photoflash lamps18 and then ultrasonically welded or otherwise joined along itsperiphery to the indented rim of the base member 12 in the usual manner.

In accordance with the present invention, the reflector 16 is composedentirely of a suitable white and opaque plastic such as polystyrene thatcontains a suitable white inorganic pigment (such as powdered magnesiumoxide or titanium dioxide) that is uniformly dispersed in the resin fromwhich the reflector is formed. A sufficient amount of the pigment isadded to crystal (colorless) styrene, for example, to make it white andopaque.

The surfaces of the reflector 16 which define the individual reflectorelements 17 for the photoflash lamps 18 thus comprise an opaque whiteplastic which, by virtue of its dull or matte finish (as compared to aspecular metallized or mirror finish), attenuates impinging light raysfrom the fired flashlamps and produces a soft diffuse beam of lightwhich has substantially the same spectral characteristics as the actinicflash produced by the lamp.

The photoflash lamps 18 are conventional miniature type photoflash lampsused in conventional flashcubes. Such photoflash lamps are well known inthe art and have a volume of about 0.6 cubic centimeter and are filledwith shredded zirconium fuel and from 6 to 8 atmospheres of oxygen. Theinvention thus permits standard flashcube lamps to be employed in theportrait flashcube rather than specially-designed flashlamps which havea lower output. This avoids the manufacturing and inventory problemswhich would inherently be encountered in the factory in making andstoring two different types of lamps that are identical or very similarin appearance.

The non-metallized reflector component 16 should reduce the brightnessof the light flash by at least 30% and preferably 50% to provide asuitably soft beam of light. The white opaque polystyrene reflectorpreviously described provided a 50% reduction, in brightness, as showngraphically in FIG. 3. As depicted by curve S, a standardzirconium-filled flashlamp and an aluminized reflector component of thetype used in a conventional flashcube produce a flash of light that hasa peak output of approximately 45,000 zonal lumens and an output ofabout 500 zonal lumen seconds at about 25 milliseconds (curve S incontrast, the white plastic reflector component 16 when used with anidentical flashlamp containing zirconium fuel had a peak output ofaround 22,000 zonal lumens (curve P) and an output of approximately 250zonal lumen seconds at 25 milliseconds (curve P As will be apparent tothose skilled in the art, the color temperature of the light flash canbe altered by using shredded hafnium foil or other materials as a fuelin place of shredded zirconium foil. A hafnium-filled flashlamp isdisclosed in US. Pat. No. 3,675,004 issued July 4, 1972 to E. A.Gulbransen et al., which patent is incorporated herein by reference.

The color temperature of the light flash can also be modified in thewell-known manner by adding bluecolored or other dyes to the plasticcover or to the lacquer coating applied to the individual flashlamps.Percussive type lamps can also be used in place of theelectrically-fired flashlamps shown in the drawing and the reflector canbe made of other suitable whitepigmented and opaque plastics such ascellulose acetate, cellulose propionate, or a suitable acrylic.

I claim as my invention:

1. A multiflash lighting device adapted for use in taking photographs atclose range, said device comprising the combination of:

a base member, a plurality of photoflash lamps mounted on said basemember, a protective cover secured to said base member in enclosingrelationship with said photoflash lamps, the walls of said cover thatare adjacent to said lamps being light transmissive, and reflectormember within said cover defining an individual reflector element foreach of said photoflash lamps, each of said reflector elements beingdisposed in operative relationship with its associated lamp, saidreflector member being composed of a plastic that contains auniformly-dispersed inorganic white pigment in an amount such that thesurfaces of the reflector elements are opaque and non-specular andreduce the peak light output of each of the flashlamp-reflectorcombinations to a value at least 30% lower than that produced by anidentical flashlamp and a reflector of the same size and configurationthat is coated with a specular layer of aluminum.

2. The multiflash device of claim 1 wherein said reflector member iscomposed of polystyrene and said white inorganic pigment is powderedmagnesium oxide or titanium dioxide.

3. The multiflash device of claim 2 wherein four photoflash lamps aremounted on said base member and the device thus comprises a four-flashunit, and said white plastic reflector member reduces the brightness ofthe reflected flash of light by approximately 50%.

4. The multiflash device of claim 3 wherein each of said lamps is aminiature flashlamp that has a volume of about 0.6 cc and is of a typethat produces a peak light output of approximately 45,000 zonal lumenswhen fired in said specular aluminum-coated reflector. I

1. A multiflash lighting device adapted for use in taking photographs atclose range, said device comprising the combination of: a base member, aplurality of photoflash lamps mounted on said base member, a protectivecover secured to said base member in enclosing relationship with saidphotoflash lamps, the walls of said cover that are adjacent to saidlamps being light transmissive, and a reflector member within said coverdefining an individual reflector element for each of said photoflashlamps, each of said reflector elements being disposed in operativerelationship with its associated lamp, said reflector member beingcomposed of a plastic that contains a uniformly-dispersed inorganicwhite pigment in an amount such that the surfaces of the reflectorelements are opaque and non-specular and reduce the peak light output ofeach of the flashlamp-reflector combinations to a value at least 30%lower than that produced by an identical flashlamp and a reflector ofthe same size and configuration that is coated with a specular layer ofaluminum.
 2. The multiflash device of claim 1 wherein said reflectormember is composed of polystyrene and said white inorganic pigment ispowdered magnesium oxide or titanium dioxide.
 3. The multiflash deviceof claim 2 wherein four photoflash lamps are mounted on said base memberand the device thus comprises a four-flash unit, and said white plasticreflector member reduces the brightness of the reflected flash of lightby approximately 50%.
 4. The multiflash device of claim 3 wherein eachof said lamps is a miniature flashlamp that has a volume of about 0.6 ccand is of a type that produces a peak light output of approximately 45,000 zonal lumens when fired in said specular aluminum-coated reflector.